I just removed an under seat gas tank from my '74 CJ. Now I have a big hole in the body where the gas filler cap used to be. I'm going to have to weld in a new piece of steel to fill the hole. My problem is I don't know exactly what gauge steel the body is made of. I'm guessing it's probably 16 or 18 gauge but I don't know for sure. Since I'm going to have to weld in the patch I need it to be the same gauge as the rest of the body so does anybody know what gauge steel the body is made of?